Motor-controller.



0. T HENDERSON & H. I. HARRIES.

MOTOR CONTROLEER. Arbucmon men nova. 1914.

1,238,516. w Patented Aug. 28, 1917.

UNITED STATES PATENT ormon.

CLARK T. HENDERSON AND HERBERT J. HARBIES, OF MILWAUKEE, WISCONSIN, ASSIGNOBS T THE CUTLER-HAMMER MFG. ('20., 0F MILWAUKEE, WISCONSIN, A

CORPORATION OF WISCONSIN.

MOTOR-CONTROLLER.

Application filed November 2, 1914. Serial No. 362L923.

To all whom it may concern:

Be it known that we, CLARK T. HENDER SON and HERBERT J. HARRIES, citizens of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wiscon sin, have invented new and useful Improvements in Motor-Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the acoompanying drawings, forming a part of this specification.

This invention relates to controllers for electric motors and more particularly to con trollers for shunt motors.

One of the objects of the invention is to provide an improved controller whereby the field strength of the controlled motor may be varied at will for speed regulation and automatically governed to insure a strong field under predetermined current conditions in the armature circuit.

A more specific object of the invention is.

to provide a controller wherein the motor field may be controlled at will and automati= cally through a common medium, such, for example, as a magnetic switch.

Various other objects and advantages of. the invention willhereinafter appear.

As will be apparent,-controllers embody ing the invention may be advantageopsly em ployed'in various difierent relations. For

example, such a controller is highly advantageous for electric vehicles, the same providin for accelerated speed of the vehicle weakening of its driving motor and yet insuring a strong field in starting and further insuring field strengthening predetermined increase in the loa on the driving motor while running with a weakened field.

The accompanying drawing diagrammatically illustrates one embodiment of the invention particularly adapted for motor ve hicles and the same will now be described, it bein understood that the invention is not limite to the specific embodiment thereof chosen for illustration.

The drawing shows a motor 1 having an armature .A and a shunt field winding F supplied with current from a storage battery '2 as is customary in electric'vehicles.

Further, the field circuit of the motor is shown as provided with two steps of resistupon a ance r and r for reducing the field strength of the motor for an increased speed. It should, of course, be understood that the number of steps of resistance may be re duced to one or increased, as desired.

The controller includes a magnetic switch 3 controlling the continuity of the motor circult, magnetic switches 4 and 5 controlling the field resistances r and r, a master switch 6 controlling the aforesaid magnetic switches,

, and an electro-responsive relay switch 7 controlling the field resistance switch 5. The relay switch 7 is preferably of the vibrating type and has its winding 7 connected in series with the motor armature.

Briefly described, the controller functions as follows:

In the first operative position of the master switch the switch 3 is energized to complots the motor circuit while the switches at and 5 are also energized to short-circuit the two steps of field resistance, thereby giving maximum field strength. In the next 0 erative position of the master switch the switch 4: is deenergized to open the short-circuit around the resistance 7' thereby including said resistance in circuit and weakening the motor field for a higher s eed. Then when the master switch is move to its third operative position the switch 5 is deenergized to open the short circuit around the resistance r, thereby'including said resistance to further weaken the motor field for a still higher speed. The relay 7, as above stated, is responsive to the armature current, and upon responding energizes switch 4 which is so connected in circuit as to short-circuit both resistances r and 1", thereby increasing the field strength to maximum. In consequence, it will be apparent, that however the master switch is o erated in starting, the relay switch 7 and t e. resistance switch 4 will insure full field strength upon increase of the armature current to the value for which said relay is set to respond and that however said master switch may be set for'running,

full field strength will also be insured by the more efiects said protection by the mere addition of a small rela acting upon one of theswitches provided or manual'regulation.

The circuit arrangement and functions of the controller will now be more specifically described: The armature circuit of the motor may be traced from the lefthand terminal of the battery 2 by conductor 10 through the winding 7 of relay switch 7, by conductor 11 through the motor armature A, by conductor 12 through the switch 3, when closed, by conductor 13 to the opposite side of the battery. The field circuit may be traced from the left hand side of the battery by conductors 10 and 14 through the resistances r and r when not short-circuited by conductor 15 through the field winding F, by conductor 16 and thence through the switch 3 when closed .to the opposlte side of the battery as al- 'sistances r and r, as already traced. The

foregoing constitutes all of the power cir-; cuits involved;

The master switch, which has illustrated in a very simplified form, includes 23 thereof by conductor 26 throng a pivoted arm movable over three contact segments 21, 22 and 23 to control the windings of switches 3, 5 and 4 respectively. In its first position the arm engages all three of said segments to ener 'ze all threeof the switches mentioned. T e energizin circuit of switch 3 extends from the left and side of the battery by conductors 10 and 14 through the master switch to segment 21 by conductor 24 through the winding '04 said switch 3, by conductors 25 and 13 to the right hand side of the battery. The energim ing circuit of switch 4 extends from the eft hand side of the battery to the master switch, as already traced, and from so elrlit t e winding of said switch 4, by cohdu tors 27 and 13 to the right hand side of the atte The energizing circuit of switch 5 exten s from segment 22 of the master switch by conductor 28 through the winding 'of said switch 5, by conductors 29, 27 and 13 to the right hand side of the battery. Thus the master switch in its first position starts the motor with full field strength. 4

'When the master switch is moved to its second position it disen es cut 23, thereby 'deenergizing switc 4 wlth 'a con- ,means controlled thereb sequent inclusion of the resistance r, and when moved to its third operative position disengages the segment 22, thereby deenergizing relay 5 w th a consequent inclusion of the resistance r, as above described.

The circuit controlled by the relay switch, 7 extends from the left hand side of the battery by conductors 10, 14 and 30 through said relay switch, by conductor 31 through the operatin winding of switch 4 to conductor 27 an thence to the right hand side of the battery. It will thus be observed that the relay switch 7 controls an energizing circuit for the switch 4 in parallel to the energizing circuit for said switch controlled by the master switch. In consequence, it

will be apparent that as above stated, switch 4 will be responsive to the relay 7 even with the master switch set in a position to deenergize the same. Likewise it will be apparent that with the relay 7 closed movement of the master switch to its'seoond or third 0 erative position will have no efiect upon. t e resistance switches until normal current conditions are reestablished in the armature circuit and the.-relay 7 released. In other words, the manual regulation of the field strength for acceleration is always subservient to the automatic regulating means.

What we claim as new and desire to secure by Letters Patent is:

1. In combination, a motor having a shunt field, ower-operated field regulating.

means there or and independently operable manual and automatic means for directin the operation of said power controll means.

2. In combination, a motor having a shunt field, power actuated field regulating means therefor and manual and automatic means for directing the operation of said Ipower actuated means, said manual means eing subservient to said automatic means for field weakening.

3. In combination, a motor having a shunt field, ower actuated field regulating means there or and manual and automatic means for directing the o eration of said power actuated means, sai manual means eing subservient to said automatic means for field weakening and said automatic means being independent of said manual means for field strengthening.

4. In combination, a motor having a shunt field, independently o erable manual and automatic means for directing field reg'ulation thereof and common means controlled thereby for effecting the directedregulation.

'5. In combination, a motor having a shunt field, manual and automatic means for directing field regulation thereof and common for eflecting the directed re ation, sai automatic means under certain current conditions in the armature circuit predominating said manual 3 tion thereof to determine the field regulation and automatic means also directing the operation of said first mentioned means to insure a predetermined field strength under abnormal current conditions in the armature circuit irrespective of said manual means and to restore fieldstrength to the value de termined by said manual means upon restoration of normal current conditions in the armature circuit.

8. In combination, a motor having a shunt field, electroresponsive field regulating means therefor, manual means controlling said electro-responsive means to vary the field strength at will and electro-responsive means responsive to variations in the armature current to also control said first mentioned means.

9. In combination, a motor having a shunt field, electro responsive field regulating means therefor, electroresponsive controlling, means for said former means responsive to-insure a predetermined field strength under certain. current conditions in the armature circuit and manual control means for said regulating means to effect reduction of the field. strength but subject to the aforesaid action of said former controlling means.

10. In combination, a motor having a shunt field, electro-responsive field regulat ing means therefor, electro-responsive means responsive to the armature current to effect energization of said first mentioned means and manual means to energize and denergize said first mentioned electro-responsive means.

11. In combination, a motor having a shunt field electro-responsive field regulating means therefor, manual means for energizing and deene'rgizing said electro-responsive means to respectively strengthen and weaken the motor field and electro-responsive means responsive to the motor current to insure energization of said first mentioned means independently of said manual means while predetermined current conditions exist in the motor circuit.

12. In combination, a motor having ashunt field, a plurality of power operated switches and means cont-rolled thereby for efiecting different de recs of field regulation and one being opera le to insure full field strength independently of the others and automatic means controllingi the operation of said last mentioned switc 13. In combination, a motor having a shunt field, a plurality of power operated switches and means controlled thereb for varying the motor field strength to di erent degrees and one of said switches being operable to effect maximum field strengthening, manual means for directing the operation of all of said switches and automatic means controlling the operation of said last mentioned switch.

14. In combination, a motor having a shunt field windin field regulating means including a plura ity of electro-responsive switches for varying the motor field strength to different degrees and one of said switches being operable to restore full field strength independently of the remainder thereof, manual means for directing operation of all of said switches and electro-re- -sponsive means responsive to the motor curautomatically close. and open said short cir- I cuit.

In witness whereof, we have each here unto subscribed our name in the presence of witnesses.

CLARK TL. HENDERSON. HERBERT J. HARRIES. 

